\(Ta.có:x+y=5\left(1\right)\\ Mặt.khác:\dfrac{xPTK_A}{31}=\dfrac{yPTK_O}{24}=\dfrac{PTK_{hc}}{31+24}=\dfrac{110}{55}=2\\ \Rightarrow xPTK_A+48=110\\ \Leftrightarrow xPTK_A=62\\ Mà:y=\dfrac{24.2}{16}=3\\\Rightarrow x=5-3=2\\ \Rightarrow CTTQ:A_2O_3\left(A:hoá.trị.\left(III\right)\right)\\ M_A=\dfrac{110-48}{2}=31\left(đ.v.C\right)\\ \Rightarrow A:Photpho\left(P=31\right)\)